1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Copyright (C) 2018 Christoph Hellwig.
  4 *
  5 * DMA operations that map physical memory directly without using an IOMMU.
  6 */
  7#ifndef _KERNEL_DMA_DIRECT_H
  8#define _KERNEL_DMA_DIRECT_H
  9
 10#include <linux/dma-direct.h>
 11
 12int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt,
 13		void *cpu_addr, dma_addr_t dma_addr, size_t size,
 14		unsigned long attrs);
 15bool dma_direct_can_mmap(struct device *dev);
 16int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
 17		void *cpu_addr, dma_addr_t dma_addr, size_t size,
 18		unsigned long attrs);
 19bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr);
 20int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
 21		enum dma_data_direction dir, unsigned long attrs);
 22size_t dma_direct_max_mapping_size(struct device *dev);
 23
 24#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
 25    defined(CONFIG_SWIOTLB)
 26void dma_direct_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,
 27		int nents, enum dma_data_direction dir);
 28#else
 29static inline void dma_direct_sync_sg_for_device(struct device *dev,
 30		struct scatterlist *sgl, int nents, enum dma_data_direction dir)
 31{
 32}
 33#endif
 34
 35#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
 36    defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \
 37    defined(CONFIG_SWIOTLB)
 38void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
 39		int nents, enum dma_data_direction dir, unsigned long attrs);
 40void dma_direct_sync_sg_for_cpu(struct device *dev,
 41		struct scatterlist *sgl, int nents, enum dma_data_direction dir);
 42#else
 43static inline void dma_direct_unmap_sg(struct device *dev,
 44		struct scatterlist *sgl, int nents, enum dma_data_direction dir,
 45		unsigned long attrs)
 46{
 47}
 48static inline void dma_direct_sync_sg_for_cpu(struct device *dev,
 49		struct scatterlist *sgl, int nents, enum dma_data_direction dir)
 50{
 51}
 52#endif
 53
 54static inline void dma_direct_sync_single_for_device(struct device *dev,
 55		dma_addr_t addr, size_t size, enum dma_data_direction dir)
 56{
 57	phys_addr_t paddr = dma_to_phys(dev, addr);
 58
 59	if (unlikely(is_swiotlb_buffer(paddr)))
 60		swiotlb_sync_single_for_device(dev, paddr, size, dir);
 61
 62	if (!dev_is_dma_coherent(dev))
 63		arch_sync_dma_for_device(paddr, size, dir);
 64}
 65
 66static inline void dma_direct_sync_single_for_cpu(struct device *dev,
 67		dma_addr_t addr, size_t size, enum dma_data_direction dir)
 68{
 69	phys_addr_t paddr = dma_to_phys(dev, addr);
 70
 71	if (!dev_is_dma_coherent(dev)) {
 72		arch_sync_dma_for_cpu(paddr, size, dir);
 73		arch_sync_dma_for_cpu_all();
 74	}
 75
 76	if (unlikely(is_swiotlb_buffer(paddr)))
 77		swiotlb_sync_single_for_cpu(dev, paddr, size, dir);
 78
 79	if (dir == DMA_FROM_DEVICE)
 80		arch_dma_mark_clean(paddr, size);
 81}
 82
 83static inline dma_addr_t dma_direct_map_page(struct device *dev,
 84		struct page *page, unsigned long offset, size_t size,
 85		enum dma_data_direction dir, unsigned long attrs)
 86{
 87	phys_addr_t phys = page_to_phys(page) + offset;
 88	dma_addr_t dma_addr = phys_to_dma(dev, phys);
 89
 90	if (unlikely(swiotlb_force == SWIOTLB_FORCE))
 91		return swiotlb_map(dev, phys, size, dir, attrs);
 92
 93	if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
 94		if (swiotlb_force != SWIOTLB_NO_FORCE)
 95			return swiotlb_map(dev, phys, size, dir, attrs);
 96
 97		dev_WARN_ONCE(dev, 1,
 98			     "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
 99			     &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
100		return DMA_MAPPING_ERROR;
101	}
102
103	if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
104		arch_sync_dma_for_device(phys, size, dir);
105	return dma_addr;
106}
107
108static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
109		size_t size, enum dma_data_direction dir, unsigned long attrs)
110{
111	phys_addr_t phys = dma_to_phys(dev, addr);
112
113	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
114		dma_direct_sync_single_for_cpu(dev, addr, size, dir);
115
116	if (unlikely(is_swiotlb_buffer(phys)))
117		swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs);
118}
119#endif /* _KERNEL_DMA_DIRECT_H */